Elastomers are typically compounded with fillers, crosslinking agents and other additives, followed by forming or shaping into a desired product configuration. This forming may be accomplished by calendering or extrusion, but most often the forming process is carried out by compression or injection molding. After shaping, the elastomer molecules are crosslinked through the action of crosslinking agents, thereby creating a three dimensional structure that provides strength and stability. Such crosslinking, or curing, is usually effected by heat and pressure. Fluoroelastomers (i.e. elastomeric fluoropolymers) are often press cured in a first step at elevated temperature and pressure while confined in a mold, and then post cured, after removal from the mold, at elevated temperatures and ambient pressures. The post cure step serves to complete the curing process. Certain fluoroelastomer compositions have a tendency to evolve undesirable quantities of gaseous byproducts during the press cure process, resulting in a sponged product, i.e., one that contains voids. This problem is described, for example, in U.S. Pat. No. 4,520,170 with respect to perfluoroelastomers.